Parasite Of Cattle Research Articles

Co-Infection of Cattle withFasciola hepaticaandMycobacterium bovis- Immunological Consequences

Fasciola hepatica, the liver fluke, is a common parasite of cattle in much of the world. Previously, we have shown that cattle infected with F. hepatica have altered responsiveness (delayed type hypersensitivity reaction and cytokine responses) to M. bovis BCG infection. We hypothesized that co-infection with F. hepatica would, likewise, alter the immune response of cattle to virulent M. bovis infection, with possible implications for disease diagnosis and disease progression. Our previous work with F. hepatica/M. bovis BCG-infected cattle demonstrated a reduction in interferon (IFN)-gamma responsiveness in co-infected animals. Similar findings are reported here with virulent M. bovis following aerosol infection. The epidemiological significance of these findings, also, require exploration, particularly in view of the considerable resources devoted to the diagnosis and eradication of bovine tuberculosis, and the high prevalence of F. hepatica infection in areas where eradication has proved difficult.

Adjuvant effect of bovine heat shock protein 70 on piroplasm surface protein, p33, of Theileria sergenti

In this study, we investigated the immunological effects of bovine heat shock protein 70 (HSP70) on the major Theileria sergenti surface protein (p33). The gene encoding p33 was expressed as a fusion protein with bovine HSP70 from a plasmid vector. The adjuvant function of HSP70 on p33 was evaluated with regard to antibody response, cytokine production, and a challenge experiment in mice or cattle. HSP-p33 fusion protein provoked higher humoral and cellular immunity than either Escherichia coli-expressed p33 or piroplasm soluble protein. The HSP adjuvant activity toward p33 was also possible to detect in the inoculated cattle. The overall growth of parasites in cattle was significantly restrained in the HSP-p33-inoculated group, up to 50–52 days longer than in the controls. The present results indicate that HSP-p33 fusion protein is a promising candidate vaccine for clinical theileriosis in the field.

Bovine immunity – a driver for diversity in Theileria parasites?

Theileria parva and Theileria annulata are tick-borne parasites of cattle that infect and transform leukocytes, causing severe and often fatal parasitic leukoses. Both species provoke strong immunity against subsequent infection. However, considerable diversity is observed in field populations of each parasite and protection is only assured against homologous challenge. The life cycles of these parasites are complex and involve prolonged exposure to host and vector defence mechanisms. Although the relevant vector mechanisms are poorly defined, protective responses of cattle seem to be tightly focused and variable in their specificity between individuals. This review considers whether bovine immunity acts as a driver for diversity in T. parva and T. annulata and explores other factors that might underlie genetic variation in these parasites.

Immunolocalization and serum antibody responses to Brugia malayi pepsin inhibitor homolog (Bm‐33)

cDNA coding for Brugia malayi pepsin inhibitor homolog (Bm-33) from the human filarial parasite was cloned in pRSET for large-scale expression and functional characterization. The pRSET-B cloned gene did not yield recombinant protein expression and the reason was attributed to the presence of an N-terminal signal peptide. The gene was subcloned in pRSET-A without a signal peptide and the 33 kDa histidine-tagged recombinant protein was purified by IMAC. All individuals from an endemic area generated IgG responses against Bm-33 in the order MF>CP>EN. Isotype analysis indicated an elevated IgG4 reactivity in the order MF>EN>CP. Bm-33-specific IgE levels were elevated in MF, CP and EN compared to non-endemic normals with no significant differences among the groups. Paraffin-embedded sections of Setaria digitata (cattle filarial parasite) stained with mouse anti-Bm-33 antibodies exhibited the hypodermal nature of Bm-33. These findings suggest that Bm-33 is an immunodominant antigen and contributes to filarial pathogenesis.

Microarray Analysis of Female- and Larval-Specific Gene Expression in the Horn Fly (Diptera: Muscidae)

The horn fly, Haematobia irritans L., is an obligate blood-feeding parasite of cattle, and control of this pest is a continuing problem because the fly is becoming resistant to pesticides. Dominant conditional lethal gene systems are being studied as population control technologies against agricultural pests. One of the components of these systems is a female-specific gene promoter that drives expression of a lethality-inducing gene. To identify candidate genes to supply this promoter, microarrays were designed from a horn fly expressed sequence tag (EST) database and probed to identify female-specific and larval-specific gene expression. Analysis of dye swap experiments found 432 and 417 transcripts whose expression levels were higher or lower in adult female flies, respectively, compared with adult male flies. Additionally, 419 and 871 transcripts were identified whose expression levels were higher or lower in first-instar larvae compared with adult flies, respectively. Three transcripts were expressed more highly in adult females flies compared with adult males and also higher in the first-instar larval lifestage compared with adult flies. One of these transcripts, a putative nanos ortholog, has a high female-to-male expression ratio, a moderate expression level in first-instar larvae, and has been well characterized in Drosophila. melanogaster (Meigen). In conclusion, we used microarray technology, verified by reverse transcriptase-polymerase chain reaction and massively parallel pyrosequencing, to study life stage- and sex-specific gene expression in the horn fly and identified three gene candidates for detailed evaluation as a gene promoter source for the development of a female-specific conditional lethality system.

Laser‐assisted microdissection for the study of the ecology of parasites in their hosts

The population biology of internal parasites is difficult to study because the adult parasites are often inaccessible, deep within the host's body. Developing stages, such as eggs in the faeces or larvae in the skin are more easily obtained, but are difficult to handle because they are often very small and with a tough cuticle. This has limited their use in molecular ecology for estimating population biology parameters of the adults (their parents). We have used Onchocerca ochengi (a filarial nematode parasite of cattle) to describe a novel and generally applicable method of easily and conveniently isolating individual larvae (microfilariae) from the host using laser-assisted microdissection. Furthermore, we have been able to improve the isolation of DNA by using the laser to bisect the larva to release DNA from the tissues enclosed within the parasite cuticle, and in this way we have achieved amplification of fragments over 1400bp, and routinely PCR-amplified single-copy sequences from 5% of the DNA from a single larva (the equivalent of approximately 15 nuclei), and regularly from 0.5%.

Genotype characterization of the Haematobia Irritans (diptera: muscidae) from Brazil, Dominican Republic and Colombia based on randomly amplified polymorphic dna (rapd) analysis

Blood-sucking flies are important parasites in animal production systems, especially regarding confinement conditions. Haematobia irritans, the horn fly, is one of the most troublesome species within bovine production systems, due to the intense stress imposed to the animals. H. irritans is one of the parasites of cattle that cause significant economic losses in many parts of the world, including South America. In the present work, Brazilian, Colombian and Dominican Republic populations of this species were studied by Random Amplified Polymorphic DNA (RAPD) to assess basically genetic variability between populations. Fifteen different decamer random primers were employed in the genomic DNA amplification, yielding 196 fragments in the three H. irritans populations. Among H. irritans samples, that from Colombia produced the smallest numbers of polymorphic bands. This high genetic homogeneity may be ascribed to its geographic origin, which causes high isolation, low gene flow, unlike the other American populations, from Brazil and Dominican Republic. Molecular marker fragments, which its produced exclusive bands, detected in every sample enabled the population origin to be characterized, but they are also potentially useful for further approaches such as the putative origin of Brazilian, Colombian and Dominican Republic populations of horn fly from South America. Similarity indices produced by chemo metric analysis showed the closest relationships between flies from Brazil and Dominican Republic, while flies from Colombia showed the greatest genotypic differentiation relative to the others populations.

The experimental establishment of ruminant nematodes in European hares ( Lepus europaeus)

The factors that control the demography of European hare Lepus europaeus populations are poorly understood, but it has been recognized that the decline of hares in Europe is associated with an increasing intensity of agricultural activity. Many mechanisms have been suggested. We propose another mechanism; a negative impact arising from ingestion of the infective larvae of ruminant livestock. We dosed juvenile hares from a worm-free colony with a conservative dose from a mixed culture of infective larvae of the nematode parasites of sheep and cattle. We examined the hares post-mortem for the establishment of those ruminant nematodes, differences in weight changes, and the shedding of eggs. We found that under the circumstances of our trial, Trichostrongylus colubriformis and to a lesser extent T. rugatus, T. vitrinus, and Teladorsagia circumcincta were able to establish as adults in the dosed animals. We found strongyle eggs in the faeces of the dosed hares, and were able to culture larvae from those eggs. However, the ecological significance of our findings, if any, remains to be elucidated. Because of their mobility, hares may transmit resistant strains of parasites between grazing properties.

Nutrición y parasitismo gastrointestinal en producción de rumiantes

En pos de aumentar el rendimiento animal, los productores se enfrentan con dos grandes obstáculos: sanidad y nutrición. La resistencia a las drogas antihelmínticas tradicionales y el incremento en la producción orgánica de alimentos están llevando a buscar alternativas para el control de los parásitos. Los parásitos producen alteraciones que afectan desde el consumo de alimentos hasta la utilización de los nutrientes ingeridos, interfiriendo gravemente en la producción. La "inmunonutrición", se considera una medida potencial y sustentable de control antipara-sitario. La disponibilidad de proteínas, vitaminas y minerales es un importante factor para optimizar la productividad y la resistencia del hospedador a ciertas parasitosis. Los metabolitos secundarios de algunas plantas pueden tener efectos antiparasitarios para los animales que las pastorean. El objetivo del presente trabajo es, basado en revisiones de trabajos de investigaciones previas, señalar algunas de las interacciones existentes entre nutrición y parasitismo en rumiantes y mostrar cómo un manejo nutricional racional puede ser considerado un método eficiente de control antiparasitario.

Tick control methods used by resource-limited farmers and the effect of ticks on cattle in rural areas of the Eastern Cape Province, South Africa

A survey to document tick control methods used by resource-limited farmers in the control of cattle ticks in the Eastern Cape Province of South Africa was conducted by interviewing 59 cattle farmers using structured questionnaires and general conversation. Information collected was on external parasites of cattle, their effects and their control methods. Ticks were reported to be a major problem causing diseases like anaplasmosis (89.8%), babesiosis (55.9%) and ehrlichiosis (16.9%), as well as wounds that predispose to screwworm infestation, tick worry and teat damage to cows troubling farmers in their farming enterprises. The main tick control methods were; acaricides provided by government, however 94.9% of the farmers interviewed were of the opinion that the dip wash is not effective in killing the ticks. As a result, farmers complement the government dipping service with their own initiatives like spraying with conventional acaricides (22%), household disinfectants such as Jeyes fluid (18.6%), used engine oil (10.2%), chickens (5.1%), manual removal (5.1%), and pouricides (1.7%). In addition, some farmers also use plants (6.8%), mainly the leaf of Aloe ferox and the bark of Ptaeroxylon obliquum. The study revealed ticks to be a major problem in the study area.

PCR-based detection of blood parasites in cattle and adult Rhipicephalus appendiculatus ticks

To ascertain the infection rate for tick-borne pathogens in Zambia, an epidemiological survey of Theileria parva, Babesia bigemina and Anaplasma marginale in traditionally managed Sanga cattle was conducted using PCR. Of the 71 native Zambian cattle, 28 (39.4%) were positive for T. parva, 16 (22.5%) for B. bigemina and 34 (47.9%) for A. marginale. The mixed infection rate in cattle was 8.5% (6/71), 16.9% (12/71), 7.0% (5/71) and 2.8% (2/71) for T. parva/B. bigemina, T. parva/A. marginale, B. bigemina/A. marginale and T. parva/B. bigemina/A. marginale, respectively. To predict the risk for transmission of tick-borne pathogens from ticks to cattle, a total of 74 Rhipicephalus appendiculatus ticks were collected from a location where cattle had been found positive for T. parva. Of the ticks collected, 10 (13.5%) were found to be PCR-positive for T. parva. The results suggest that the infection rate for tick-borne pathogens was relatively high in Sanga cattle and that adult R. appendiculatus ticks were highly infected with T. parva.

Ultrastructural study of a tetratrichomonad isolated from pig fecal samples

Trichomonads found in pigs include the commensal Tritrichomonas suis (more well known because of its synonymy to Tritrichomonas foetus, a trichomonad parasite of cattle and other animals) and Tetratrichomonas buttreyi, which appear similar to Tritrichomonas suis under the light microscope. A trichomonad isolated from pig fecal samples was subjected to scanning and transmission electron microscopy for ultrastructural study. The organism's ultrastructure revealed features commonly found in trichomonads; however, features such as the number and length of flagella, type of undulating membrane, general body form, and shape and location of organelles such as the nucleus, Golgi complex, and hydrogenosomes indicated that the isolated trichomonad is not Tritrichomonas suis nor Tritrichomonas foetus. Polymerase chain reaction (PCR) corroborated these results. Moreover, the ultrastructure was similar to the ultrastructure of previously described tetratrichomonads. It is especially suggested that the isolate is T. buttreyi. These findings could be of significance in the differentiation among different porcine trichomonads in diagnostic procedures. In addition, this is the first known detailed ultrastructural study of T. buttreyi isolated from pigs; thus, this can serve as an aid for future comparison between porcine and bovine T. buttreyi.

A molecular survey of Theileria and Babesia parasites in cattle, with a note on the distribution of ticks in Tunisia

A molecular survey of Theileria and Babesia parasites in cattle, with a note on the distribution of ticks in Tunisia

Theileria annulata induces abberrant T cell activation in vitro and in vivo.

The protozoan parasite of cattle, Theileria annulata, causes a severe lymphoproliferative disease, developing initially in the draining lymph node, which is often fatal in naive animals. Infection of macrophages with T. annulata leads to an augmentation of their antigen-presenting capability in vitro and infected cells can induce proliferation of autologous resting T cells from naive animals. This inappropriate activation of T cells may play an important role in the failure of the host to mount an effective immune response in vivo. To investigate this hypothesis we characterized further the response of T cells from naive cattle to infected cells in vitro, and also examined the development of the immune response in lymph nodes draining the sites of T. annulata infection. Both CD4+ and CD8+ T cells from naive peripheral blood mononuclear cells (PBMC) were induced to proliferate and express the activation markers IL-2R and MHC class II when cultured with infected cells. This effect was seen in both 'naive' and 'memory' T cells, and was dependent upon contact with infected cells. In vitro, infected cells are therefore capable of activating T cells irrespective of their antigen specificity or memory status. In draining lymph nodes, although large numbers of IL-2R+ cells developed following infection, these activated cells were only associated with areas of parasite-induced proliferating cells, and subsequently disappeared from the node. Cells expressing IL-2R were not present in recognized sites for T cell development. Germinal centres were severely affected, losing T cell-dependent zones followed by a total destruction of morphology. T cell function is therefore severely disrupted within draining nodes. This study has shown that parasitized cells supply sufficient signals in vitro to activate T cells irrespective of specificity. T cells also are not stimulated in a conventional manner in vivo, and this may play an important role in preventing an effective immune response from being generated.

Hospedeiros de Triplasta atrocoxalis (Ashmead) (Hymenoptera: Figitidae: Eucoilinae) coletados em fezes de bovinos e búfalos no Brasil

This study verified the percentage of parasitism and hosts species of the parasitoid Triplasta atrocoxalis (Ashmead) (Hymenoptera: Figitidae: Eucoilinae) in cattle and buffalo dung, collected in the South of Goias state, Brazil; from January 1998 to June 2004. The pupae were obtained by the flotation method. They were individually placed in gelatin capsules until the emergence of adult dipterous or their parasitoids. The percentage of parasitism in cattle and buffalo dung was 2.5% % and 0.1%, respectively.

A molecular survey of Theileria and Babesia parasites in cattle, with a note on the distribution of ticks in Tunisia

Between October and November 2006, a total of 278 bovine blood samples were examined, and 104 (37.4%) were positive for piroplasms by microscopy. A reverse line blot hybridisation with polymerase chain reaction detected Theileria annulata, T. buffeli, Babesia bovis and B. bigemina in cattle accounting for 48.6% of positive samples. The most frequently found species was T. buffeli, which was present in 39.2% of the samples. T. annulata was found in 48 samples (17.3%). Babesia infections were less frequently detected: B. bovis was found in 6.8% of the samples and B. bigemina in 4.3%. Mixed infections were detected in 45 samples, accounting for seven different combinations of species. Seven Ixodid tick species (Boophilus annulatus, Ixodes ricinus, Hyalomma marginatum, Hyalomma excavatum, Hyalomma detritum, Haemaphysalis punctata and Haemaphysalis sulcata) were collected from examined cattle in the 23 visited farms. I. ricinus was the dominant species (36%), mainly collected in the humid zone, while it seemed to be very rare in the semi-arid zone (where only 15 specimens were collected), whereas B. annulatus was the most commonly collected species in the sub-humid area (68.5% of ticks collected in this zone).

Restricted genetic diversity in the ubiquitous cattle parasite, Sarcocystis cruzi

Although parasites of the genus Sarcocystis have likely cycled between bovine herbivores and canine carnivores for tens of millions of years, humans may have profoundly influenced the ecology and evolution of those prevalent in domesticated dogs and cattle. To preliminarily assess the possibility of such anthropogenic effects, we surveyed genetic variation in conserved (18S small subunit) and variable (ITS-1) portions of ribosomal DNA from a large sample of Sarcocystis cruzi occurring in taurine beef cattle raised in the United States and Uruguay, and compared these data to available homologues, including those reported from zebu cattle, water buffalo, and bison. For additional context, we compared the apparent diversity of cattle parasites to that reported from congeneric parasites in other hosts. We find that the S. cruzi of taurine cattle, whether derived from the Americas or Asia, are devoid of variability in the sequenced portion (80%) of the small subunit rDNA. By contrast, geographically limited samples of related parasites in other hosts, including those of wildlife, are more variable. At the adjacent ITS-1 locus, allelic distribution patterns did not indicate any regional barriers to gene flow, suggesting that the parasite may have been introduced to the Americas via a common source such as domesticated dogs or cattle. Thus, human impact on this parasite's distribution and diversification would seem to have been great.

Traditional Tannin-Treatment Against Intestinal Parasites in Sheep and Cattle

Around  the  world  indigenous  groups  have  traditionally used  leaves,  bark  and  roots  containing  tannins  to  treat diarrhea and intestinal parasites in humans and livestock. Traditional veternary medicine has largely been replaced by pharmaceuticals throughout most of the world. My aim is to revitalize traditional veternary practices and connect them to novel research. This study iincludes a literature re-view based mostly on three articles about condensed tan-nins (CT), all from New Zealand: Barry & McNabb (1999), Niezen et al. (1995 & 1996), and Høeg (1974). These are considered in light of my observations and experiences of beneficial effect  from  feeding sheep with high-tannin  for-age. CT have been reported  to  increase absorption of essen-tial amino acids  in  the small  intestines. This  results  inin-creased  wool  growth,  body  mass,  milk  production  and amount of protein in milk. CT seem to counteract protein loss caused by gut parasitism and may stimulate the im-mune system. CT may also inactivate parasite larvae dur-ing passage through the gut. Forage containing CT could offer  a  nutritionally-based  ecologically  syustainable  sys-tem for controlling the effects of parasites. Tannins might also be a way to reduce the large amount of grain fed to sheep and cattle. Traditional   practices could be a means  to better health and  economy  for  traditional  societies. This  is  especially important when crops containing CT are available in great amounts  or  can  be  grown  in mountain  ro  cold  districts where grains are difficult to grow.

Social bacteria and asocial eukaryotes

The end of 2007 brought us draft genome sequences of two eukaryotic microorganisms, Babesia bovis and Malassezia globosa, as well as complete genomes of the ammonia-oxidizing archaeal chemoautotroph Nitrosopumilus maritimus, and several environmental bacteria (Table 1). In terms of genome size, this list covers both sides of the spectrum: the 245 kb genome of an obligate insect symbiont Sulcia muelleri is the second smallest microbial genome sequenced so far, whereas the 13 033 kb chromosome of the social myxobacterium Sorangium cellulosum breaks the record as the largest bacterial genome – and the largest DNA molecule in the prokaryotic world.

Vaccine testing of a recombinant activation‐associated secreted protein (ASP1) from Ostertagia ostertagi

Previous vaccination trials against the economically important cattle parasite Ostertagia ostertagi have indicated the protective capacity of activation-associated secreted proteins (ASPs). The further development of these antigens into a commercial vaccine will require their recombinant expression. The aim of the current study was to clone and express Oo-asp1 in a baculovirus expression system and to evaluate the protective capacity of the recombinant protein against an O. ostertagi challenge infection in cattle. The full coding sequence of Oo-asp1 was cloned in a baculovirus expression vector in frame with a carboxy-terminal Histidine tag and recombinant virus was used to infect an insect cell culture. Western blot analysis with anti-His and anti-Oo-ASP1 antibodies showed the production of recombinant Oo-ASP1. The cell pellet containing the recombinant was subsequently used to immunize seven calves three times intramuscularly with QuilA as adjuvant. Control animals were solely injected with the QuilA adjuvant. The challenge infection with O. ostertagi consisted of 30,000 L3 larvae per animal given over 30 days (1000 larvae/day, 5 days/week) and started the same day as the final immunization. Immunization with the recombinant Oo-ASP1 did not result in any level of protection against the challenge infection. There was no reduction in faecal egg output or in worm burdens. Moreover, Western blot analyses and ELISA indicated that, although the animals raised an antibody response against the recombinant Oo-ASP1, there was hardly a response against the native Oo-ASP1, suggesting that the baculovirus expressed recombinant was wrongly folded or lacked essential secondary modifications. Further analysis of the structure of the native ASPs and their glycosylations is being done.